Cell carbon content and biomass assessments of dinoflagellates and diatoms in the oceanic ecosystem of the Southern Gulf of Mexico

LORENA PATRICIA LINACRE ROJAS (2021, [Objeto de congreso])

This study assessed the cell carbon content and biomass for genera of dinoflagellates and diatoms in the oceanic ecosystem of the Southern Gulf of Mexico. Carbon content estimates were based on biovolume calculations derived from linear dimension measurements of individual cells and the approximate geometric body shape of each genus. Then, biomass assessments were performed for both groups in two gulf regions (Perdido and Coatzacoalcos) using these carbon content factors and cell abundances. After four seasonal cruises, 11,817 cells of dinoflagellates and 3,412 cells of diatoms were analyzed. Diverse body shapes and cell sizes were observed among 46 dinoflagellate genera and 37 diatom genera. Nano-cells of dinoflagellates (68% <20 μm) and micro-cells of diatoms (77% 20–200 μm, mostly 50–75 μm) were predominant. According to this cell-size structure, on average, diatoms contained 40% more carbon per cell than dinoflagellates. Contrasting carbon content estimates were observed within the genera of both microalgae. Large carbon averages (>10,000 pg C cell-1) were attributed to Gonyaulacal and some occasional genera of dinoflagellates (e.g., Pyrocystis and Noctiluca) and centric diatoms. In contrast, values up to 3 orders of magnitude lower were found for Peridinial and Gymnodinial dinoflagellates and pennate diatoms. Based on these carbon content estimates, which can be considered representative for most of this oceanic ecosystem, seasonal and regional differences were found in the biomass assessments conducted for these functional groups. Overall, dinoflagellates (mostly low-carbon Gymnodinales) had larger depth-integrated biomass than diatoms (mainly rich-carbon centric forms) within the euphotic zone. An exception to it was the late-summer cruise at the Coatzacoalcos region when a surface bloom of centric diatoms was observed in stations influenced by river runoff. This work contributes useful reference information for future ecological studies and models for understanding the biogeochemical functioning of this open-ocean ecosystem. © 2021 Linacre et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Carbon, biomass, Oceanic ecosystem, Southern Gulf of Mexico, Mexico CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO OCEANOGRAFÍA OCEANOGRAFÍA

Hyperiid amphipods from the Gulf of Ulloa and offshore region, Baja California: The possible role of the gelatinous zooplankton as a transport vector into the coastal shelf waters

Bertha Lavaniegos (2020, [Artículo])

Hyperiid amphipod species from the Gulf of Ulloa, Baja California, and the adjacent region (from the shelf break to 200 km offshore) were analyzed to evaluate diversity and abundances. This productive area supports small-scale commercial fisheries, including sand bass (Paralabrax nebulifer), California spiny lobster (Panulirus interruptus), abalones, clams, and others. Strong coastal upwelling events were observed during summer seasons of the period 2002-2008 between Punta Eugenia and Punta Abreojos. The upwelling plumes at Punta Abreojos are transported southward in slope waters bordering the coastal shelf of the Gulf of Ulloa, contributing to the separation of coastal and oceanic regions, and explain differences in amphipod diversity and abundances between both regions. In the offshore region, the most abundant species were Vibilia armata, Lestrigonus schizogeneios, Primno brevidens, and Eupronoe minuta, similar to previous findings in northern regions of Baja California and southern California. However, abundances of these species were lower (10-30 individuals/1000 m3), only reaching 20-50% of abundance levels reported off northern Baja California. In the coastal shelf of the Gulf of Ulloa, amphipods were virtually absent during 2002, 2003 and 2006. However, during 2004 and 2005, abundances of P. brevidens increased (54 and 20 ind/1000 m3, respectively). Moreover, during the late summer of 2007, abundances of L. schizogeneios, P. brevidens, Lycaea nasuta, Lycaea pulex, and Simorhynchotus antennarius increased considerably (261, 39, 31, 68, 416 ind/1000 m3, respectively), indicating occasional utilization of the coastal shelf by pelagic amphipods. Changes in gelatinous populations (medusae, siphonophores, ctenophores, doliolids, and salps) paralleled changes in hyperiid populations, with highest abundances in 2005-2008 in the coastal shelf. Significant correlations of 17 amphipod species with gelatinous taxa, which are often used as host organisms by hyperiid amphipods, suggest that gelatinous presence enhanced hyperiid abundance and promoted the progression of hyperiid amphipods onto the coastal shelf during parts of the 2002-2008 period. © 2020 Bertha E. Lavaniegos. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

abalone, Amphipoda, article, Baja California, clam, clinical article, Ctenophora, Eugenia, female, fishery, human, human experiment, male, medusa, nonhuman, Panulirus interruptus, plume, summer, zooplankton, Amphipoda, animal, California, ecosystem, CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO OCEANOGRAFÍA OCEANOGRAFÍA

Diversidad de fauna asociada al sargazo (Sargasum fluitans y Sargasum natans) y su relación con las características físicas del agua en el norte del Caribe mexicano

HELDER ABRAHAM BERZUNZA PASOS (2024, [Tesis de maestría])

CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO HIDROLOGÍA HIDROBIOLOGÍA HIDROBIOLOGÍA

Discurso y esfera pública : mujer y prensa en Hermosillo, Sonora : el caso de los periódicos El Pueblo y El Tiempo (1934-1938).

ELIZABETH CEJUDO RAMOS (2007, [Tesis de maestría])

CIENCIAS SOCIALES Periodismo Análisis del discurso Medios impresos Mujeres en los medios

The impact of digital transformation and value capture on business models

RAUL FRANCISCO MONTALVO CORZO (2023, [Artículo])

In awareness of the importance that Digital Transformation (DT) has gained in Mexican companies in recent years, as well as the concern of Business Models (BM) in capturing value, the purpose of this thesis is to answer the question:

What is the impact of Digital Transformation and value capture on business models?

Five research projects have been developed in Mexico to answer this question. The first research work consisted of a systematic literature review in order to identify relevant opportunities for this research, which is explained in the first chapter of the thesis. Derived from this first research work, the following four research papers were developed.

The second chapter addresses the adoption of the digital transformation of corner stores promoted by large companies. Through the application of in-depth interviews in corner stores resulted in an urgent call for large companies to unify strategies to promote the DT of the front desk with customers.

The third chapter includes an analysis of the sustainability reports of large companies, in which DT actions to achieve sustainability are identified. Concluding that investment in digital transformation actions promote the sustainability of businesses and the permanence of business models.

A successful business model considers satisfactory customer experience as a pillar in its development. Which motivated the fourth paper, focused on investigating how artificial intelligence is perceived in customer service. It was through surveys that we investigated whether the implementation of chatbots improves the customer experience, findings show that it will depend on the purpose of the chatbot, the age of the customer and the level of education.

With the purpose of sharing experiences of Mexican companies in the implementation of DT projects, a fifth research paper is included explaining why digital transformation projects fail in companies. This work was carried out by conducting interviews with Project Managers (PM) and experts in DT projects implementation.

This work is original since it is developed in Mexico, has different research methodologies and has managerial implications that are mentioned in each research paper. There are undoubtedly great opportunities in the research of DT, since it is a topic with many edges, and this thesis only covers some of them.

Doctor of Business Administration

CIENCIAS SOCIALES CIENCIAS ECONÓMICAS ECONOMÍA DEL CAMBIO TECNOLÓGICO INNOVACIÓN TECNOLÓGICA

Effects of geostrophic kinetic energy on the distribution of mesopelagic fish larvae in the southern Gulf of California in summer/fall stratified seasons

FERNANDO CONTRERAS CATALA (2016, [Artículo])

Effects of geostrophic kinetic energy flux on the three-dimensional distribution of fish larvae of mesopelagic species (Vinciguerria lucetia, Diogenichthys laternatus, Benthosema panamense and Triphoturus mexicanus) in the southern Gulf of California during summer and fall seasons of stronger stratification were analyzed. The greatest larval abundance was found at sampling stations in geostrophic kinetic energy-poor areas (<7.5 J/m3), where the distribution of the dominant species tended to be stratified. Larvae of V. lucetia (average abundance of 318 larvae/10m2) and B. panamense (174 larvae/10m2) were mostly located in and above the pycnocline (typically ∼ 40 m depth). In contrast, larvae of D. laternatus (60 larvae/10m2) were mainly located in and below the pycnocline. On the other hand, in sampling stations from geostrophic kinetic energy-rich areas (> 21 J/m3), where mesoscale eddies were present, the larvae of the dominant species had low abundance and were spread more evenly through the water column, in spite of the water column stratification. For example, in a cyclonic eddy, V. lucetia larvae (34 larvae/10m2) extended their distribution to, at least, the limit of sampling 200 m depth below the pycnocline, while D. laternatus larvae (29 larvae/10m2) were found right up to the surface, both probably as a consequence mixing and secondary circulation in the eddy. Results showed that the level of the geostrophic kinetic energy flux affects the abundance and the three-dimensional distribution of mesopelagic fish larvae during the seasons of stronger stratification, indicating that areas with low geostrophic kinetic energy may be advantageous for feeding and development of mesopelagic fish larvae because of greater water column stability. © 2016 Contreras-Catala et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Article, autumn, Benthosema panamense, Diogenichthys laternatus, environmental factor, environmental parameters, fish, geographic distribution, geostrophic kinetic energy, hydrography, larva, nonhuman, population abundance, population dispersion, pop CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO OCEANOGRAFÍA OCEANOGRAFÍA

Freshwater exchanges and surface salinity in the Colombian basin, Caribbean Sea

Emilio Beier (2017, [Artículo])

Despite the heavy regional rainfall and considerable discharge of many rivers into the Colombian Basin, there have been few detailed studies about the dilution of Caribbean Surface Water and the variability of salinity in the southwestern Caribbean. An analysis of the precipitation, evaporation and runoff in relation to the climate variability demonstrates that although the salt balance in the Colombian Basin overall is in equilibrium, the area south of 12N is an important dilution sub-basin. In the southwest of the basin, in the region of the Panama-Colombia Gyre, Caribbean Sea Water is diluted by precipitation and runoff year round, while in the northeast, off La Guajira, its salinity increases from December to May by upwelling. At the interannual scale, continental runoff is related to El Niño Southern Oscillation, and precipitation and evaporation south of 12°N are related to the Caribbean Low Level Jet. During El Niño years the maximum salinification occurs in the dry season (December-February) while in La Niña years the maximum dilution (or freshening), reaching La Guajira Coastal Zone, occurs in the wet season (September-November). © 2017 Beier et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

sea water, fresh water, Article, Caribbean, dilution, dry season, El Nino, environmental parameters, evaporation, freshwater exchange, geographic distribution, molecular weight, oscillation, precipitation, river basin, salinity, seasonal variation, s CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO OCEANOGRAFÍA OCEANOGRAFÍA

Dipole-wind interactions under gap wind jet conditions in the Gulf of Tehuantepec, Mexico: A surface drifter and satellite database analysis

MAURO WILFRIDO SANTIAGO GARCIA (2019, [Artículo])

Gap wind jets (Tehuano winds) trigger supersquirts of colder water and mesoscale asymmetric dipoles in the Gulf of Tehuantepec (GT). However, the effects of successive gap wind jets on dipoles and their effects inside eddies have not yet been studied. Based on the wind fields, geostrophic currents, and surface drifter dispersion, this research documented three dipoles triggered and modified by Tehuano winds. Once a dipole develops, successive gap wind jets strengthen the vortices, and the anticyclonic eddy migrates southwestward while the cyclonic eddy is maintained on the east side of the GT. During the wind relaxation stage, the cyclonic eddy may propagate westward, but due to the subsequent re-intensification of the Tehuano winds, the vortex could break down, as was suggested by surface drifter dispersion pattern and geostrophic field data. The effect of the Tehuano winds was evaluating via eddy-Ekman pumping. Under Tehuano wind conditions, Ekman downwelling (upwelling) inside the anticyclonic (cyclonic) eddies may reach ~ -2.0 (0.5) m d-1 and decrease as the wind weakens. In the absence of Tehuano winds, Ekman downwelling inside the anticyclonic eddy was ~ 0.1 (-0.1) m d-1. The asymmetry of downwelling and upwelling inside eddies during Tehuano wind events may be associated with Tehuano wind forcing. © 2019 Santiago-García et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

article, dipole, leisure, Mexico, cold, ecosystem, factual database, geographic mapping, hurricane, Mexico, satellite imagery, season, water flow, wind, sea water, Cold Temperature, Cyclonic Storms, Databases, Factual, Ecosystem, Geographic Mapping, CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO OCEANOGRAFÍA OCEANOGRAFÍA

Agricultura, agua y cambio climático en zonas áridas de México

SALVADOR EMILIO LLUCH COTA JUAN ALBERTO VELAZQUEZ ZAPATA César Nieto Delgado (2022, [Artículo])

"En este artículo se expone cómo a pesar de que la ciencia y la tecnología han permitido aumentar históricamente la productividad agrícola, hoy día existen grandes retos derivados del cambio climático y la crisis global de abastecimiento de agua. Se comentan algunas medidas de adaptación y manejo del recurso agua, con algunas referencias a nuestra realidad nacional, y se argumenta cómo el enfoque de Nexo, que implica la toma de decisiones sobre el uso del recurso agua de forma transectorial, representa una alternativa de adaptación al cambio climático."

Cambio climático, agricultura, agua, Nexo, adaptación Climate change, agriculture, water, nexus, adaptation CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO CLIMATOLOGÍA CLIMATOLOGÍA REGIONAL CLIMATOLOGÍA REGIONAL

Recomendaciones en la creación de un portal en línea para comercializar monederos electrónicos de vales de despensa a prospectos privados

ERIK VAZQUEZ PEDROZA (2023, [Otro, Trabajo de grado, maestría])

Muchas empresas otorgan como prestación social a sus empleados monederos electrónicos de vales de despensa. La

contratación de este servicio en la mayoría de los casos se hace por medios físicos, pero la realidad es que dicha

contratación puede generarse de forma electrónica. Las empresas están cambiando su forma de contratación al medio digital, e incluso los clientes en algunos casos buscan empresas que les ahorren tiempo en procesos. Da un valor el facilitarle procesos a clientes, empleados, disminuyendo tiempos de contratación e incluso gastos en mensajería,

gasolina de ejecutivos y tiempo e incluso mitigar riesgos respecto a pérdida de contratos originales o daño en ellos. la realidad es que las empresas poco a poco migrarán sus procesos a nuevas tecnologías o a tecnologías disruptivas y en

muchos casos por solicitud de sus clientes quienes buscan disminuir procesos. Por medio del presente trabajo se darán

recomendaciones para poder implementar la contratación de forma electrónica analizando temas de datos personales, electrónica, derecho de los consumidores, marcas, nombres de dominio, entre otros.

Contratos Protección de datos Firma electrónica Marcas INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LAS TELECOMUNICACIONES TECNOLOGÍA DE LAS TELECOMUNICACIONES